diff --git a/base/abstractarray.jl b/base/abstractarray.jl
index 57d835cd67f77..e2fa45a58c88e 100644
--- a/base/abstractarray.jl
+++ b/base/abstractarray.jl
@@ -1583,10 +1583,14 @@ eltypeof(x::AbstractArray) = eltype(x)
 promote_eltypeof() = error()
 promote_eltypeof(v1) = eltypeof(v1)
 promote_eltypeof(v1, vs...) = promote_type(eltypeof(v1), promote_eltypeof(vs...))
+promote_eltypeof(v1::T, vs::T...) where {T} = eltypeof(v1)
+promote_eltypeof(v1::AbstractArray{T}, vs::AbstractArray{T}...) where {T} = T
 
 promote_eltype() = error()
 promote_eltype(v1) = eltype(v1)
 promote_eltype(v1, vs...) = promote_type(eltype(v1), promote_eltype(vs...))
+promote_eltype(v1::T, vs::T...) where {T} = eltype(T)
+promote_eltype(v1::AbstractArray{T}, vs::AbstractArray{T}...) where {T} = T
 
 #TODO: ERROR CHECK
 _cat(catdim::Int) = Vector{Any}()